51805880640 has 448 divisors, whose sum is σ = 190265425920. Its totient is φ = 13255280640.

The previous prime is 51805880627. The next prime is 51805880641. The reversal of 51805880640 is 4608850815.

51805880640 is a `hidden beast` number, since 5 + 1 + 8 + 0 + 588 + 0 + 64 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51805880641) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 34014919 + ... + 34016441.

Almost surely, 2^51805880640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51805880640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95132712960).

51805880640 is an abundant number, since it is smaller than the sum of its proper divisors (138459545280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51805880640 is a wasteful number, since it uses less digits than its factorization.

51805880640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1707 (or 1691 counting only the distinct ones).

The product of its (nonzero) digits is 307200, while the sum is 45.

The spelling of 51805880640 in words is "fifty-one billion, eight hundred five million, eight hundred eighty thousand, six hundred forty".